Displacement Sensor Device

Abstract

A displacement sensor device ( 1 ) comprising a fibre bragg grating sensor ( 2 ) and a downshift unit ( 3 ). The downshift unit ( 3 ) is connected to the fibre bragg grating sensor ( 2 ), a first ( 4 ) and a second fastening device ( 5 ). The first fastening device ( 4 ) is connected to the downshift unit ( 3 ), and the second fastening device ( 5 ) is connected to the fibre bragg grating sensor ( 2 ), a container ( 6 ) enclosing the fibre bragg grating sensor ( 2 ), the downshift unit ( 3 ), at least partially the first ( 4 ) and the second fastening device ( 5 ), and at least partially an optical fibre ( 7 ). Furthermore the sensor device ( 1 ) comprises at least one fixing component ( 8 ). The at least one fixing component ( 8 ) is arranged between one of the fastening devices ( 4, 5 ) and the container ( 6 ).

1 . A displacement sensor device ( 1 ) comprising
 a fibre bragg grating sensor ( 2 ) for sensing displacements in the surrounding environment where the displacement sensor device ( 1 ) is fastened,   a downshift unit ( 3 ) for downshifting the displacements towards the fibre bragg grating sensor ( 2 ) which the displacement sensor device ( 1 ) is affected by when installed, wherein the downshift unit ( 3 ) is connected to the fibre bragg grating sensor ( 2 ),   a first ( 4 ) and a second fastening device ( 5 ) for fastening of the displacement sensor device ( 1 ) in the surrounding environment, wherein the first fastening device ( 4 ) is connected to the downshift unit ( 3 ), and the second fastening device ( 5 ) is connected to the fibre bragg grating sensor ( 2 ),   a container ( 6 ) enclosing the fibre bragg grating sensor ( 2 ), the downshift unit ( 3 ), at least partially the first ( 4 ) and the second fastening device ( 5 ), and at least partially an optical fibre ( 7 ),   
       characterised in that the sensor device ( 1 ) comprises
 at least one fixing component ( 8 ), for holding the fastening devices ( 4 ,  5 ) in position so that a predefined distance between the fastening devices ( 4 ,  5 ) is fixed, wherein the at least one fixing component ( 8 ) is arranged between one of the fastening devices ( 4 ,  5 ) and the container ( 6 ), further wherein the at least one fixing component ( 8 ) is arranged to break or deform when a force applied to the displacement sensor device ( 1 ) is greater than a predefined value. 
 
     
     
         2 . A displacement sensor device ( 1 ) according to  claim 1 , wherein the at least one fixing component ( 8 ) is fabricated out of a brittle material, for instance a polymer. 
     
     
         3 . A displacement sensor device ( 1 ) according to  claim 1 - 2 , wherein the container ( 6 ) or the first ( 4 ) and/or the second fastening device ( 5 ) comprises at least one fixing component ( 8 ). 
     
     
         4 . A displacement sensor device ( 1 ) according to  claim 1 - 3 , wherein the downshift unit ( 3 ) comprises a draw spring ( 9 ) and a drag link ( 10 ), wherein a longitudinal end portion of the draw spring ( 9 ) is connected to a longitudinal end portion of the drag link ( 10 ). 
     
     
         5 . A displacement sensor device ( 1 ) according to  claim 1 - 4 , comprising a draw spring ( 9 ) matching a predefined measurement interval of the displacement sensor device ( 1 ), the draw spring ( 9 ) belonging to a plurality of draw springs ( 9 ) with different spring rates. 
     
     
         6 . A displacement sensor device ( 1 ) according to  claim 1 - 5 , wherein the container ( 6 ) is made out of a solid material, for instance a metal, a polymer or a carbon fibre, withstanding a predefined force. 
     
     
         7 . A displacement sensor device ( 1 ) according to  claim 1 - 6 , comprising at least one communication channel ( 11 ) connected to the fibre bragg grating sensor ( 2 ), wherein the communication channel ( 11 ) provides communication to/from the displacement sensor device ( 1 ). 
     
     
         8 . A displacement sensor device ( 1 ) according to  claim 1 - 7 , comprising at least one protection component ( 12 ) arranged in between the container ( 6 ) and the first fastening device ( 4 ) and/or in between the container ( 6 ) and the second fastening device ( 5 ) for protecting the internal components of the downshift unit ( 3 ) from the external environment. 
     
     
         9 . A displacement sensor device ( 1 ) according to  claim 1 - 8 , comprising at least one fastening device ( 4 ,  5 ) connected to an extension unit ( 13 ) or to a plurality of extension units ( 13 ) connected in series, for extension to another displacement sensor device ( 1 ) or to an extension fastening device ( 14 ) or to a plurality of extension fastening devices ( 14 ) connected in series. 
     
     
         10 . A displacement sensor system ( 15 ) according to any of the  claims 1 - 9 , comprising a plurality of displacement sensor devices ( 1 ) connected in series.